Can we upgrade Graphic Card for Mid-2012 MacBook Pro

The GPU chip is part of the logic board so cannot be upgraded. As others have discussed it is possible to connect an external box via Thunderbolt into which you can fit a standard PCIe vide card. Some software will take advantage of this e.g. DaVinci, Final Cut Pro X, and some will not.

Your MacBook Pro being a 2012 model is now five years old and therefore considerably slower than current models. On top of that it is only an i5 CPU rather than an i7. As you have 16GB you already have the maximum amount of RAM it supports. However I suspect you still have the original hard drive fitted. An option would be to replace this with an SSD drive. This would have to be a SATA III 2.5" SSD drive like the Samsung 850 EVO, this would be much faster than the current hard drive but still a lot slower than the PCI SSD in the latest MacBook Pro.

I would therefore suggest the following three choices in order of preference.

1. SSD drive
2. Sell it and get a new MacBook Pro
3. Thunderbolt external GPU aka eGPU

Actually you can,

you can use an external GPU solution such as Bizon

https://support.bizon-tech.com/hc/en-us/articles/210709869

you may also be interested in Wofle which is trying to use Kickstarter to do the same thing

https://thewolfe.io/

however PS and Dreamweaver are not GPU intensive, and MAYA is not GPU intensive unless you are working in something that is utilizing GPU acceleration.

I suggest you post an etrecheck report to review your system and see if something installed is causing latency.

www.etrecheck.com

agreed the SSD will make a huge improvement on that system, especially since you already have 16GB RAM, but the i5 bottleneck with 3D apps like Maya will be evident regardless, it will be doable but a quad i7 at a similar clock speed would be more fitting, or dual quad xeons. Part of the problem is the software is becoming more robust and as a result older CPU's that were once at the top tier are showing their limits with newer software, especially when it's something demanding. Maya may be the most taxing thing out there along with a host of 3D animation titles who actual requirements compared to the newest games is significant.

Id put the eGPU at #2, externally you can get a more powerful GPU in that system than you can from Apple on their newest MBP for a fraction of the cost but your computer will only be as fast as it's slowest component.

No you can't.